Typebar drive including reciprocating linear moving cyclic means



July 29, 1969 J. o. scHAEFE'R 3,453,024

TYPE -DRIVE INCLUDING RECIPROCATING NEAR MOVING CYCLIC MEANS Filed Sept.18, 1967 2 Sheets-Sheet 1 INVENTOR. JOHN 0. SGHAEFER Mamm ATTORNEYUnited States Patent 3,458,024 TYPEBAR DRIVE INCLUDING RECIPROCATINGLINEAR MOVING CYCLIC MEANS John O. Schaefer, Lexington, Ky., assignor toInternational Business Machines Corporation, Armonk, N.Y.,

a corporation of New York Filed Sept. 18, 1967, Ser. No. 668,416 Int.Cl. B41j 23/08, 23/38 US. Cl. 19717 21 Claims ABSTRACT OF THE DISCLOSUREA powered typewriter has each of its pivotally mounted typebars driventhrough a linearly moving bail to print the characters thereon. Thetypebar drive mechanism has means to regulate the force with which theselected character strikes the platen in accordance with the area of thecharacter being printed. The mechanism includes means to store a secondcharacter during printing of the first character whereby typebarclashing is prevented. The typebar drive mechanism also includes meansto prevent repeat actuation of a typebar until its keylever is releasedand returned to its rest position by the typist. The mechanism also hasmeans to absorb part of the rebound energy of the typebar and itsconnecting linkage.

In powered typewriters having a typebar drive mechanism, the typebar hasnormally been driven from a power roll or a fluted drive shaft. Whilethis type of drive mechanism is satisfactory, the present invention isan improvement thereover by eliminating the requirement for a power rollor a fluted drive shaft and utilizing a linearly moving bail. As aresult, the number of parts required for the typebar drive mechanism issubstantially reduced in comparison with the number of parts required bya typebar drive mechanism utilizing a power roll or a fluted shaft.Accordingly, the typebar drive mechanism of the present invention has arelatively lower cost.

While a typebar drive mechanism has previously been suggested in whichan oscillating bail has been employed to drive the typebar in place ofthe power roll or the fluted drive shaft, this mechanism has utilized aplurality of parts between the character selection member and theconnecting link of the typebar. Thus, this previously suggested typebardrive mechanism utilizing an oscillating bail has not substantiallyreduced the cost in comparison with a typebar drive mechanism utilizinga power roll or a fluted shaft.

The present invention satisfactorily solves the foregoing problem byemploying a single actuating member between the character selectionmember and the connecting link of the typebar. Since this singleactuating member may be easily stamped, a substantial reduction in costis provided by the present invention in comparison with the previouslysuggested typebar drive mechanism utilizing an oscillating bail.

In the previously suggested typebar drive mechanism having anoscillating bail, the depression of a second keylever is prevented untilcompletion of the print cycle of the prior selected character. Whilethis prevents any clashing of the typebars since only one typebar can beselected, this substantially slows the operation of the machine. Thatis, the typist cannot select characters at a high rate of speed.

The present invention satisfactorily solves this problem by permittingthe striking of two keys at a high rate of speed without permitting anyclashing of the typebars. In the present invention, the striking of twokeys at a high rate of speed results in the second character beingstored until completion of the first print cycle. Since each print cycleof the mechanism of the present invention requires only sixty-fivemilliseconds, the typist is not aware of this character storage feature.Therefore, the speed of the typist is not retarded by the typebar drivemechanism of the present invention.

Since the various type characters have different areas, uneven typeimpressions will occur if the typebar were to move each character intoengagement with the platen at the same velocity irrespective of therelative area of the character. While typebar drive mechanisms utilizinga power roll or a fluted drive shaft have previously employed typecontrol impression means, the previously suggested typebar drivemechanism utilizing an oscillating bail does not suggest control of itsprinting impression.

The present invention satisfactorily solves this problem by utilizing amechanism having a linearly moving bail in which the force with whichthe character strikes the platen is varied in accordance with the areaof the character being printed. Thus, the maximum force occurs with thearea of largest character while the minimum force occurs with thecharacter having the smallest area.

In power operated typewriters, the rebound energy has presented aproblem wherein the possibility of clashing or jamming of typebars hasexisted. In the prior typebar drive mechanisms, the typebar has usuallydepended upon engagement of the typebar with a rest bar to absorb therebound energy. In certain instances, the typebar may oscillate uponinitially striking the rest bar whereby the possibility exists that anadjacent typebar would engage this oscillating typebar during the nextprint cycle. Thus, the rebound energy has tended to limit the speed ofoperation of the machine.

The present invention satisfactorily solves the foregoing problem byutilizing an additional rebound energy absorber in which the typebar isimmediately brought to rest so that there is no oscillation thereof. Inthe present invention, the separate rebound energy absorbing meanscooperates with the actuating member to also lock the actuating memberin its rest position.

An object of this invention is to provide a printing mechanism having atypebar drive mechanism of relatively low cost.

Another object of this invention is to provide a printing mechanism inwhich rapid selection of the type characters by the operator may occurwith the characters being printed in the order of selection.

A further object of this invention is to provide a printing mechanismutilizing a linearly moving bail in which the print force varies inaccordance with the area of the character being printed.

Still another object of this invention is to provide a poweredtypewriter in which clashing of the typebars is eliminated while stillobtaining printing of the characters in the desired order.

The foregoing and other objects, features and adv-antages of thisinvention will be apparent from the following more particulardescription of a preferred embodiment of the invention, as illustratedin the accompanying drawings.

In the drawings:

FIG. 1 is a schematic perspective view of a portion of the typebar drivemechanism of the present invention.

FIG. 2 is a side elevational view, partly in section, of a portion ofthe typebar drive mechanism of the present invention.

FIG. 3 is a timing chart showing the relationship of certain elements ofthe typebar drive mechanism during a print cycle.

FIG. 4 is an exploded perspective view of a portion of the linearlymoving bail of the typebar drive mechanism of the present invention.

FIG. 5 is a perspective view of a portion of the typebar drive mechanismof the present invention.

Referring to the drawings and particularly FIGS. 1 and 2, there is showna typewriter having a plurality of keylevers 11 (two shown in FIG. 1)with each of the keylevers 11 being pivotally mounted on a rod 12 havingits ends supported in the frame of the typewriter 10. Each of thekeylevers 11 has a keybutton 14 on one end thereof for actuation by atypist.

Each of the keylevers 11 cooperates with a separate actuating member orlever 15 to cause printing of a selected type character at a printingposition when the keylever 11 is actuated by depressing the keybutton 14to overcome a spring (not shown) urging the keylever 11 to its restposition. The keylever 11 has a dependent leg 16 with a projection 17 atthe lower end of the leg. The projection 17 has its end surface engageend surface of a tab 18 on the actuating member 15 whereby the actuatingmember 15 is moved by the keylever 11.

Each of the actuating members 15 is mounted on a rod 19 having its endssupported by the frame of the typewriter 10. Each of the actuatingmembers 15 has a slot 20 through which the rod 19 extends whereby theactuating member 15 may both pivot and slide forward and rearward.

The upper end of the actuating member 15 has one end of a link 21pivotally connected thereto. The other end of the link 21 is pivotallyconnected to a typebar 22 having a pair of type characters 23 and 24thereon in spaced relation to each other. The type character 23 is alower case character while the type character 24 is an upper casecharacter.

The typebar 22 is pivotally mounted on an arcuate fulcrum wire 25. Whenthe typebar 22 is pivoted about the wire 25, one of the type characters23 and 24 is printed through engagement of the selected characteragainst a platen 26. It should be understood that paper (not shown) willbe passed around the platen 26 and a ribbon (not shown) will beinterposed between the type characters 23 and 24 and the paper to causeprinting of the selected character on the paper.

The actuating member 15 has a first portion 27 extending rearwardly fromthe actuating member 15 for cooperation with a linearly moving bail 28,which includes a driving comb 29 and a guide comb 30. The combs 29 and30 are fixedly secured together for linear movement together.

The driving comb 29 has a plurality of resiliently biased fingers 31with each having a slot 32 therein of a shorter length than slots 33 ina plate, which forms the guide comb 30. Furthermore, the lower end ofeach of the slots 33 is disposed beneath the lower end of each of theslots 32.

Each of the slots 32 and 33 in the combs 29 and 30, respectively,cooperates with the first portion 27 of one of the actuating members 15.When the first portion 27 of one of the actuating members 15 is movedrearwardly due to actuation of the cooperating keylever 11, the lowersurface of the first portion 27 will be positioned for engagement by thebottom surface of the slot 32. Thus, when the linearly moving bail 28 ismoved upwardly, the actuating member 15 is moved to cause the selectedtype character 23 or 24 on the typebar 22 to be printed. It should beunderstood that the position of the bottom surface of the slot 33 withrespect to the first portion 27 of the actuating member 15 is such thatthere is never any contact of the bottom surface of the slot 33 with thefirst portion 27.

The linear movements of the bail 28 are produced by rotation of a driveshaft 34. The drive shaft 34 has earns 35 (one shown) on each endthereof for cooperation with pivotally mounted cam followers 36 (oneshown). Each of the cam followers 36 is pivotally connected to one ofthe ends of the bail 28 through being secured to an ear 37 (one shown)on the guide comb 30. The profile of each 4 of the cams 35 is such thatrotation of the drive shaft 34 through results in a completereciprocating movement of the bail 28 whereby the bail 28 is cyclic inoperation. Thus, each cycle of the drive shaft 34 is 180 of rotationthereof.

Accordingly, whenever one of the actuating members 15 has its firstportion 27 moved into a position in which the lower surface of the slot32 in the drive comb 29 can engage the lower surface of the firstportion 27, the actuating member 15 is ready for movement by the bail28. When this occurs, the typebar 22 is pivoted to cause printing of oneof the characters 23 and 24 thereon.

In order for the first portion 27 of one of the actuating members 15 tobe disposed in a position for its lower surface to be engaged by thebottom surface of the cooperating slot 32 of the drive comb 29, a secondportion 38, which extends rearwardly from the first portion 27, musthave entered an aligned slot 39 in a ball interlock 40. The ballinterlock comprises a tubular member 41, which is supported by the frameof the typewriter 10, with the slots 39 formed therein and each of theslots 39 aligned with one of the second portions 38 of the actuatingmember 15. Each end of the tubular member 41 is closed, and a pluralityof balls 42 is disposed within the tubular member 41.

The total spaces between the balls 42 within the tubular member 41 aregreater than the width of one of the second portions 38 but less thanthe width of two of the second portions 38 of the actuating members 15.Accordingly, the ball interlock 40 prevents pivoting of more than one ofthe typebars 22 at the same time for printing. This insures that thereis no clashing between any of the typebars 22 due to the typist rapidlyhitting two of the keybuttons 14.

Accordingly, when the actuating member 15 is moved rearwardly bydepression of the keylever 11 due to the cooperation of the slot 20 withthe rod 19, the second portion 38 of the actuating member 15 must enterthe aligned slot 39 in the ball interlock 40 before the lower surface ofthe first portion 27 is disposed for engagement by the bottom surface'ofthe slot 32 of the drive comb 29. Therefore, unless none of the otheractuating members 15 has its second portion 38 within the ball interlock40, the actuating member 15 cannot be disposed for actuation by thelinearly moving bail 28.

When the actuating member 15 is in its rest or inoperative position, alatching surface 43 on the actuating member 15 bears against the topsurface of a resilient finger 44 adjacent its end. Each of the actuatingmembers 15 cooperates with one of the resilient fingers 44 with theresilient fingers 44 extending from a support plate 45, which issupported by the frame of the typewriter 10. The resilient fingers 44are biased in an upward direction.

When one of the keylevers 11 is moved downwardly by depressing thekeybutton 14, the cooperating actuating member 15 attempts to sliderearwardly. If none of the other actuating members 15 is disposed withinthe ball interlock 40, then the actuating member 15 may have its secondportion 38 move into the aligned slot 39 in the ball interlock 40. Whenthe second portion 38 of the actuating member 15 has entered the ballinterlock 40, the latching surface 43 is removed from engagement withthe resilient finger 44 whereby the resilient finger 44 moves upwardlyto contact a bail 46, which is crank mounted on the frame of thetypewriter 10.

The upward movement of the bail 46 pivots a lever 47 counterclockwise tocause actuation of a clutch 48. When the lever 47 is pivotedcounterclockwise, it ceases to hold one of two diametrically disposedlugs 49 of the clutch 48. When the clutch 48 is actuated, the driveshaft 34 is driven by a motor 50 through a toothed belt 51.

When the bail 46 is moved upward to actuate the clutch 48, the remainderof the print cycle cannot be interrupted so that the print cycle will becompleted. Thus, the keyboard operation is completely serial.Furthermore,

the bail 46 functions as a defined trip point since the print cycle willbe completed whenever the bail 46 is tripped.

The clutch 48 is of the helical spring type as more particularly shownand described in U.S. Patent 2,919,002 to Palmer. When the lever 47ceases to hold the lug 49 of the clutch 48, a shaft 52 is connected tothe drive shaft 34. The shaft 52 is connected to a pulley 53, which hasthe toothed belt 51 passing thereover to cause continuous rotationthereof.

Accordingly, actuation of the clutch 48 results in the drive shaft 34being rotated through 180. (The engagement of the lever 47 with theother of the lugs 49 disconnects the clutch 48) whereby the bail 28moves upwardly and then downwardly. During upward movement of the bail28, the drive comb 29 causes pivoting of the actuating member wherebythe typebar 22 is pivoted about the wire 25 to print the selectedcharacter.

The profiles of the cams are such that the typebar 22 is powered by themotor through the drive shaft 34 for only 62 of pivotal movement of thetypebar 22 toward the platen 26. The remaining 30 of pivoting of thetypebar 22 about the wire 25 until engagement with the platen 26 occursis due to momentum created by the powered movement during the first 62of pivoting of the typebar 22.

When the resilient finger 44 clears the latching surface 43 to actuatethe bail 46, the end surface of the resilient finger 44 contacts asecond latching surface 54 on the actuating member 15. This results inthe resilient finger 44 latching the actuating member 15 in a positionin which the second portion 38 of the actuating member 15'may be movedby the drive comb 29 of the linearly moving bail 28 to cause pivoting ofthe actuating member 15.

The end surface of the resilient finger 44 remains in contact with thelatching surface 54 until pivoting of the typebar 22 through its first36 (15 milliseconds) is com pleted. At this time, the tab 18 of theactuating member 15 engages the top surface of the resilient finger 44to remove the end of the resilient finger 44 from engagement with thelatching surface 54. As a result, the resilient finger 44 is disposed soas to no longer push upwardly on the bail 46.

The actuating member 15 and the typebar 22 are driven by the driveshaft34 until the actuating member 15 and the typebar 22 have pivoted through62. When the drive shaft 34 completes 62 of rotation of the cams 35, theprofiles of the earns 35 are such that the cams 35 no longer acceleratethe linearly movable bail 28 as they did during the first 62 of rotationof the drive shaft 34. Thus, the acceleration of the actuating member 15and the typebar 22 in comparison with the acceleration of the bail 28 issuch that the actuating member 15 will move away from the drive comb 29during the remaining 30 of rotation of the drive shaft 34 during whichthe bail 28 continues to be moved upwardly. However, this decelerationof the bail 28 is necessary to change its direction of movement after 90of rotation of the drive shaft 34 to insure that the bail 28 returns toits original position during the second 90 of rotation of the driveshaft 34.

Since the earns 35 decelerate the upward movement of the bail 28 after62 of pivoting of the actuating member 15 and the typebar 22, theactuating member 15 and the typebar 22 are no longer driven. However,they continue to pivot, due to momentum, until the type character 23 or24 engages the platen 26 to print the selected character.

When the actuating member 15 has pivoted 62, a depending finger on theactuating member 15 engages a rod 56, which is fixed to the frame of thetypewriter 10. This results in the actuating member 15 ceasing to pivotabout the rod 19 and starting to pivot about the fulcrum formed betweenthe rod 56 and the depending finger 55 of the actuating member 15.

Thus, during the final 30 of pivoting of the typebar 22 toward theplaten 26, the movement of the actuating member 15 is about the fulcrumbetween the depending finger 55 of the actuating member 15 and the rod56. This results in the actuating member 15 not only pivoting but alsosliding forward relative to the rod 19 due to the slot 20.

The force with which the type character 23 or 24 strikes the platen 26is regulated in accordance with the area of the character being typed.Thus, characters of large area (W, for example) require a greater forceto strike the platen 26 than characters of small area (i, for example).By varying the force with which the character strikes the platen 26 inaccordance with the area of the character, a substantially uniformprinting impression is produced.

The force with which the selected character engages the platen 26 iscontrolled in the present invention by varying the resisting force ofeach of the resilient fingers 44 against which the tab 18 of theactuating member 15 engages during pivoting of the typebar 22 to itsprinting position whereby the velocity of the typebar 22 is regulated.The control of the velocity of the typebar 22 by the resilient finger 44occurs only after powered drive of the actuating member 15 and thetypebar 22 by the drive shaft 34 has ceased.

It should be understood that the resilient finger 44 always exerts anupward force when engaged with the actuating member 15 due to theresiliency of the finger 44. However, the restraining or resisting forceof the resilient finger 44 is that force created due to changing thefulcrum point of the resilient finger 44.

If a character with the largest area is to be printed, then norestraining force against downward movement of the resilient finger 44by the tab 18 of the actuating member 15 except for the inherentresilient force of the resilient finger 44 would occur until the platen26 is engaged by the selected character on the typebar 22. However, if aminimum force is required due to the selected character having thesmallest area, then the resilient finger 44 tends to resist the movementof the tab 18 from the time that powered movement of the actuatingmember 15 ceases.

An impression control means determines the resistance by each of theresilient fingers 44. The impression control means includes a curved bar57, which is pivotally mounted on the frame of the typewriter 10 aboutthe center of curvature of the curved bar 57. The curved bar 57 has afirst set of screws 58 and a second set of screws 59 threadedly mountedtherein. One of the screws 58 of the first set and one of the screws 59of the second set cooperate with each of the resilient fingers 44. Thescrews 58 cooperate with the fingers 44 when one of the lower casecharacters 23 is to be printed. The screws 59 of the second setcooperate with the resilient fingers 44 when the selected character isone of the upper case characters 24.

The distance that each of the screws extends from the surface of thecurved bar 57 determines the force with which the typebar 22 moves theselected character into engagement with the platen 26. Thus, if thescrew does not extend beyond the surface of the curved bar 57, then theresilient finger 44 does not exert any force against movement of theactuating member 15 until the character strikes the platen 26 wherebythe typebar 22 has its greatest velocity and strikes the platen 26 withthe greatest force.

When the screw extends a maximum distance from the surface of the curvedbar 57, the resilient finger 44 resists the pivotal movement of theactuating member 15 from the time that powered movement of the actuatingmember 15 and the typebar 22 ceases. Thus, the angular velocity of theactuating member 15 and the typebar 22 is reduced to a minimum so thatthe force with which the selected character strikes the platen 26 is aminimum.

This would occur when a character of the smallest area was beingprinted.

In the position shown in FIG. 1, the curved bar 57 is positioned withthe first set of the screws 58 adapted to cooperate with the resilientfingers 44. This is with the fulcrum wire 25 positioned so that thelower case characters 23 will be printed.

The second set of the screws 59 cooperates with the resilient fingers 44when one of the upper case characters 24 is to be printed. This positionis obtained by depressing a shift key (not shown) to cause downwardmovement of the fulcrum wire 25 and counterclockwise pivoting of thecurved bar 57. The shift mechanism is preferably of the type shown anddescribed in pages 90 to 98 of IBM Customer Engineering InstructionManual For Standard Typewriter, Model C-l, Copyrighted 1960.

When shifting occurs, the curved bar 57 is pivoted by a link 60, whichis connected through suitable linkage (not shown) to the shiftmechanism. This linkage would be connected to th segment support of theshift actuating mechanism shown in FIGURE 93 on page 91 of the aforesaidIBM Customer Engineering Instruction Manual.

In addition to the impression control means in which the force withwhich the typebar 22 causes the selected character to strike the platen26 is regulated in accordance with the area of the character beingtyped, there also is provided a manual impression control means for useby the typist. This manual control means permits the typist to varyproportionally the force with which each of the characters strikes theplaten 26.

This manual impression control means is not utilized to change the forcewith which the character strikes the platen 26 in accordance with itsarea. Instead, this manual impression control means is employed todetermine whether printing will be light or heavy. For example, agreater force from each of the characters would be desired when manycarbons are being typed so that heavy printing would be desired.

This manual impression control means includes a rod 61 (see FIG. 2)having its opposite ends supported in slots in the frame of thetypewriter 10. The rod 61 is supported on a plate 62 during itsmovements by the typist. One end of the rod 61 would be connectedthrough suitable linkage to an exterior control knob for movement by thetypist.

In the position shown in FIG. 2, the rod 61 is positioned to permit thegreatest force to be exerted when a character strikes the platen 26. Asthe rod 61 is moved away from a stop 63 on the plate 62, it changes thefulcrum position of all of the resilient fingers 44. As a result, theforce with which the character strikes the platen 26 is reduced due tothe resilient finger 44 resisting movement by the tab 18 of theactuating member earlier during the pivoting of the actuating member 15after its powered rotation is stopped. The position of the rod 61determines the resisting force of the resilient finger 44 to themovement of the actuating member 15. Thus, as the rod 61 moves away fromthe stop 63, the resilient finger 44 exerts a greater resisting force tothe movement of the acutating member 15 after its powered drive ceases.

When the typebar 22 completes printing of the selected character, itrebounds away from the platen 26 with a substantial force due to theengagement of the type character with the platen 26. This rebound energyof the typebar 22, the link 21, and the actuating member 15 must beabsorbed. All of this rebound energy has previously been absorbed by arest bar 64. The rest bar 64 is curved in the same manner as the wire soas to cooperate with each of the typebars 22.

In the present invention, a portion of this rebound energy is absorbedby a resilient finger 65, which is supported on a casting 66 fixed tothe frame of the typewriter 10. The resilient finger 65 has its lowerend 67 hearing against a latching surface 68 of the actuating member 15.Thus, as the actuating member 15 returns to its rest position, thelatching surface 68 engages against the lower end 67 of the finger tocause absorption of the rebound energy whereby there is no oscillationof the actuating member 15 due to the rebound energy. The lower end 67of the finger 65 also latches the actuating member 15 against movementwhen it is not selected by movement of the cooperating keylever 11.

A stop 69 is supported by the casting 66 on the rear side of the finger65 and prevents the rebound energy from moving the latching surface 68of the actuating member 15 past the lower end 67 of the finger 65. Thus,the stop 69 insures that there is no oscillation of the actuating member15 due to the rebound energy.

The casting 66 also supports a plurality of resilient fingers 70forwardly of the fingers 65. Each of the fingers 70 cooperates with oneof the actuating members 15 by bearing against a curved portion 71 ofthe actuating member 15 to continuously urge the member 15 to its restposition.

The casting 66 also has a guide 72 attached thereto for cooperation withthe guide comb 30 of the linearly moving bail 28. The linearly movingbail 28 is continuously urged counterclockwise by springs 73 (one shown)connecting each of the cam followerrs 36 to the guide comb 30 of thebail 28.

It should be understood that the casting 66 has slots formed therein forcooperation with each of the actuating members 15. This permits movementof the actuating member 15 without any contact with the casting 66.

When the actuating member 15 returns to its rest position, the endsurface of the tab 18 is spaced from the end surface of the projection17 of the depending leg 16 of the keylever 11 (as shown in FIG. 1) ifthe typist has released the keylever 11. However, if the typist shouldnot release the keylever 11 but maintain it depressed, the projection 17of the keylever 11 will be disposed above the tab 18 when the actuatingmember 15 returns to its rest position. Accordingly, the tab '18 of theactuating member 15 will engage a cam surface 74 beneath the projection17 to cam the depending leg 16 of the keylever 11 to the side and out ofthe path of the tab 18 of the actuating member 15 to permit theactuating member 15 to return to its rest position. As a result, thedepression of the keylever 11 by the typist cannot cause another cyclefor the cooperating actuating member 15 until the keylever 11 isreleased and again depressed.

When the keylever 11 is released, it returns from a position in which itis disposed at the side of the tab 18 to the position of FIG. 1 whereinthe end surface of the projection 17 is disposed in spaced relation tothe end surface of the tab 18. In this position, depression of thekeylever 11 results in the actuating member 15 again being shiftedrearwardly to move through another of its print cycles.

Considering the operation of the typewriter of the present invention, itwill be assumed that all of the keylevers 11 are in their rest ornon-depressed positions. When one of the keylevers 11 is depressed, theactuating member 15 is pushed rearwardly to move the second portion 38into the aligned slot 39 in the ball interlock 40. When this occurs, thelower surface of the first portion 27 of the actuating member 15 isdisposed for engagement by the bottom surface of the slot 32 in thedrive comb 29. When sufiicient rearward sliding of the actuating member15 due to the slot 20 cooperating with the rod 19 has occurred becauseof the depression of the keylever 11, the top surface of the resilientfinger 44 no longer engages the latching surface 43 of the actuatingmember 15. As a result, the resilient finger 44 moves upwardly to raisethe bail 46. As soon as the resilient finger 44 clears the latchingsurface 43, it engages the latching surface 54 during its upwardmovement of the bail 46 whereby the upward movement of the bail 46 islimited.

The upward movement of the bail 46 causes counterclockwise pivoting ofthe lever 47 to allow the clutch 48 to connect the shaft 52 to the driveshaft 34 whereby the motor 50 rotates the drive shaft 34. When the bail46 is tripped by being moved upwardly by the resilient finger 44, theactuating member ceases to slide rearwardly since it is at its rearmostposition due to the length of the slot 20. In this position, the lowersurface of the first portion 27 of the actuating member 15 is disposedfor engagement by the bottom surface of the slot 32 in the drive comb29. This insures that the actuating member 15 is pivoted when thelinearly moving bail 28 is moved upwardly.

As shown in the timing cycle of FIG. 3, the actuating member 15 does notslide but only pivots when the actuating member 15 is being driven bythe motor 50. As shown at point 75 in the timing cycle of FIG. 3 forindicating the pivotal movement of the actuating member 15, the secondportion 38 of the actuating member 15 is removed from the aligned slot39 in the ball interlock 40 after about 30 (twelve milliseconds) ofrotation of the actuating member 15.

When the second portion 38 of the actuating member 15 is removed fromthe aligned slot 39 of the ball interlock 40, another of the actuatingmembers 15 may have its second portion 38 enter its aligned slot 39 inthe ball interlock 40. Thus, a selected character may be stored duringthe additional part of the cycle by the mechanism of the presentinvention due to the removal of the first of the actuating members 15from the ball interlock 40. This permits the typist to rapidly hit twoof the keybuttons 14 and have both selected characters printed in thedesired sequence. However, because of the ball interlock 40, there is nopossibility of two of the typebars 22 clashing since only one of thetypebars 22 can be actuated for printing.

The driving of the actuating member 15 continues until 62 of pivotalmovement thereof is completed. At this time, the drive comb 29 ceases toengage the first portion 27 of the actuating member 15 to end driving ofthe actuating member 15 by the linearly moving bail 28. At the sametime, the depending finger 55 of the actuating member 15 engages thefulcrum rod 56. Thus, forward motion of the actuating member 15 occursas shown in the timing cycle of FIG. 3 for indicating sliding motion ofthe actuating member 15.

The forward motion of the actuating member 15 ceases before thecompletion of the cycle. Therefore, the first portion 27 of theactuating member 15 is removed from the slot 32 in the drive comb 29before the drive comb 29 returns to its rest position.

When the depending finger 55 engages the rod 56, pivoting of theactuating member 15 occurs about the rod 56 until printing of theselected character occurs. Thereafter, pivoting of the actuating member15 is about the rod 19 until the print cycle is completed.

As previously mentioned, the force with which the selected characterengages the platen 26 is determined by the velocity of the typebar 22.The velocity of the typebar 22 is regulated by the position of the screw58 of the first set of the screws or the screw 59 of the second setdepending on whether the character 23 or the character 24 is beingprinted. This position of the screw determines when the resilient finger44 bears against the tab 18 to restrict the pivotal motion of theactuating member 15. It should be understood that the resilient finger44 is in engagement with the tab 18 during its driven movement but thefinger 44 cannot be engaged with one of the screws in the curved bar 57until free flight movement starts.

When the character has been printed, the momentum from the engagement ofthe character with the platen 26 results in the typebar 22 returninguntil it abuts against the rest bar 64. At the same time, the latchingsurface 68 of the actuating member '15 contacts the lower end 67 of theresilient finger 65 whereby the rebound energy is obsorbed. This alsoprevents any oscillation of the actuating member 15.

If a second of the keylevers 11 has been actuated by the typist beforecompletion of a print cycle of a first of the actuating members 15, thesecond actuating member 15 will be stored in the ball interlock 40 untilthe completion of the cycle of the first actuating member 15. Therearward motion of the second actuating member 15 into the ballinterlock 40 results in the cooperating resilient finger 44 ceasing toengage the latching surface 43 of the second actuating member 15 wherebythe finger 44 maintains the bail 46 in an upper position to hold thepivoted lever 47 in a position so that it does not engage the next ofthe lugs 49 of the clutch 48. As a result, the clutch 48 remains engagedto cause another cycle of the drive shaft 34 to occur.

When the second of the keylevers 11 is actuated before completion of theprior print cycle, the drive comb 29 is not in its lowermost position sothat the first portion 27 of the second of the actuating members 15 willnot enter the slot 32 in the resilient finger 31 but merely pushes theresilient finger 31 rearwardly. However, as soon as the drive comb 29returns to its lowermost position at the end of the print cycle, thefinger 31 moves forwardly to cause the slot 32 to receive the firstportion 27 whereby the lower surface of the first portion 27 is engagedby the bottom surface of the slot 32 to start another print cycle.

The solid line position of the bail in the timing cycle of FIG. 3 iswhen another of the keylevers 11 is not actuated. If a second of thekeylevers 11 is actuated, then the ball 46 will again raise upwardly at30 and remains in the upward position until another cycle starts asindicated by the dotted line. When this occurs, the bail 46 would movedownwardly at the start of the next cycle in the same manner as shown inFIG. 3.

It should be noted that the resilient finger 44 reaches its lowermostposition at the completion of the free flight of the actuating member15. Thereafter, as the actuating member 15 pivots back to its restposition, the resilient finger 44 returns to its rest position byfollowing the movement of the actuating member 15.

An advantage of this invention is its relatively low cost. Since theactuating member 15 performs the functions of several diflerent leversof presently available typebar drive mechanisms, this substantiallyreduces the cost. Furthermore, all of the parts of the typebar drivemechanism of the present invention may be formed by stamping so thatthis also substantially decreases manufacturing costs.

Another advantage of this invention is that it reduces the number ofparts required for a typebar drive mechanism by eliminating the need fora power roll or fluted drive shaft. Still another advantage of thisinvention is that it eliminates typebar clashing. A further advantage ofthis invention is that it permits the storage of one type characterwhile another is being printed.

While the invention has been particularly shown and described withreference to a preferred embodiment thereof, it will be understood bythose skilled in the art that various changes in form and details may bemade therein without departing from the spirit and scope of theinvention.

What is claimed is:

1. A mechanism for printing a selected type character at a printingposition comprising:

a plurality of character selection members;

a plurality of actuating means equal in number to said characterselection members;

each of said character selection members cooperating with one of saidactuating means to move said actuating means; each of said actuatingmeans having at least one type character connected thereto for printingat the printing position when said actuating means is actuated;

cyclic means cooperating with each of said actuating means;

said cyclic means including reciprocating means for engaging each ofsaid actuating means when said actuating means is disposed in anactuating position;

said reciprocating means of said cyclic means actuating one of saidactuating means to print the selected character at the printing positionafter said one actuating means is moved by said cooperating characterselection member into the actuating position;

said reciprocating means of said cyclic means having yieldable meanscooperating with each of said actuating means to prevent actuation ofanother of said actuating means during movement of said one actuatingmeans by said reciprocating means of said cyclic means, said yieldablemeans allowing actuation of said another actuating means by saidreciprocating means of said cyclic means after movement of said oneactuating means is completed; and

means to store the selection of another character connected to saidanother actuating means and selected during actuation of said oneactuating means by said reciprocating means of said cyclic means;

said storage means positioning said another actuating means forautomatic engagement by said reciprocating means of said cyclic means inthe next cycle of said cyclic means.

2. The mechanism according to claim 1 including:

means to drive said cyclic means;

and means to activate said drive means after said cooperating characterselection member moves said one actuating means into position forcooperation with said cyclic means.

3. A mechanism for printing a selected type character at a printingposition comprising:

a plurality of character selection members;

a plurality of actuating means with each of said actuating meanscooperating with one of said character selection members;

each of said actuating means having at least one type characterconnected thereto for printing when said actuating means is actuated;

means cooperating with each of said actuating means,

said cooperating means actuating one of said actuating means to printthe selected character at the printing position after said one actuatingmeans is moved by said cooperating character selection member into aposition for cooperation with said cooperating means; and

means cooperating with each of said actuatin means to regulate the forcewith which each of said actuating means moves the character connectedthereto into engagement with a platen to print the character inaccordance with the area of the character;

said force regulating means including:

a plurality of resilient fingers, each of said resilient fingersengaging one of said actuating means; and

means to vary the force exerted by each of said resilient fingersagainst said actuating means in accordance with the area of thecharacter.

4. The mechanism according to claim 3 including:

means to activate said cooperating means in response to movement of saidcharacter selection member; and

said activating means including said cooperating resilient finger ofsaid force regulating means.

5. The mechanism according to claim 3 in which said 6. The mechanismaccording to claim 4 in which said resilient finger latches saidactuating means in position for engagement with said cooperating means.

7. The mechanism according to claim 3 in which said cooperating means iscyclic.

8. The mechanism according to claim 3 in which said cooperating meansengages said actuating means when said cooperating means actuates saidactuating means, said cooperating means ceasing to engage said actuatingmeans before the selected character engages the platen; and

said force regulating means being effective only after said cooperatingmeans ceases to engage said actuating means.

9. A mechanism for printing a selected type character at a printingposition comprising: a plurality of character selection members;

a plurality of actuating means with each of said actuating meanscooperating with one of said character selection members;

each of said actuating means having at least one type characterconnected thereto for printing when said actuating means is actuated;

reciprocating linear moving cyclic means cooperating with each of saidactuating means, said cyclic means actuating one of said actuating meansto print the selected character at the printing position when said oneactuating means is moved by said cooperating character selection memberinto a position for cooperation with said cyclic means, said cyclicmeans imparting a substantially constant energy to each said actuatingmeans independent of the area of the character connected thereto; and

means engaging said actuating means when said actuating means is inmotion to regulate the force with which each of said actuating meansmoves the character connected thereto into engagement with a platen toprint the character in accordance with the area of the character, saidengaging means regulating the force by removing a portion of thesubstantially constant energy imparted to said actuating means by saidcyclic means.

10. The mechanism according to claim 9 including means to store theselection of another character connected to another of said actuatingmeans after said one actuating means is actuated by said cyclic means,said 40 force regulating means also functioning as said storage means.

11. The mechanism according to claim 6 in which:

said actuating means includes an actuating member;

a plurality of typebars with each of said typebars having at least onetype character thereon for printing when said typebar is actuated;

means to connect each of said actuating members to one of said typebars;and resilient means engaging each of said actuating members to absorbrebound energy of said typebar, said connecting means, and saidactuating member after the selected character has been printed.

12. A mechanism for printing a selected type character at a printingposition comprising:

a plurality of character selection members;

a plurality of actuating means with each of said actuatmg meanscooperating with one of said character selection members;

each of said actuating means having at least one type characterconnected thereto for printing when said actuating means is actuated;

cyclic means cooperating with each of said actuating actuating means toprint the selected character means is moved by said cooperatingcharacter selec- 6 tion member into a position for cooperation with saidcyclic means;

and means to regulate the force with which each of said actuating meansmoves the character connected thereto into engagement with a platen toprint the character in accordance with the area of the character;

silient fingers engaging one of said actuating means; and

means to vary the force exterted by each of said resilient fingersagainst said actuating means in accordance with the area of thecharacter. 13. The mechanism according to claim 6 in which each of saidactuating means has two characters connected thereto; and sadi forcevarying means has:

means to vary the force of each of said resilient fingers against saidactuating means in accordance with the area of one of said characterswhen said one character is to be printed; and means to vary the force ofeach of said resilient fingers against said actuating means inaccordance with the area of the other of said characters when said othercharacter is to be printed. 14. The mechanism according to claim 9including: means to activate said cyclic means in response to movementof said character selection member; and said activating means includingsaid cooperating resilient finger of said force regulating means. 15. Amechanism for printing a selected type character at a printing positioncomprising:

a plurality of character selection members;

a plurality of actuating members with each of said actuating membtrscooperating with one of said character selection members;

a plurality of typebars with each of said typebars having at least onetype character thereon for printing when said typebar is actuated;

each of said actuating members being mounted for pivotal and slidingmovement and connected to one of said typebars;

reciprocating means to cooperate with each of said actuating members;

said actuating member being movable only in a first direction by saidcooptrating character selection member is actuated whereby saidactuating member is positioned for engagement by said reciprocatingmeans;

means to retain said actuating member in position for engagement by saidreciprocating means, said retaining means urging said actuating memberinto the position in which it is engaged by said reciprocating meansuntil said reciprocating means ceases to drive said actuating member atwhich times said retaining means becomes ineffective; and

said reciprocating means moving in a direction substantially normal tothe first direction when said reciprocating means is actuated, saidretaining means and said reciprocating means cooperating when saidreciprocating means is actuated so that said reciprocating means onlypivots said actuating member as long as said reciprocating means engagessaid actuating member to cause printing of the selected character at theprinting position.

1-6. A mechanism for printing a selected type character at a printingposition comprising:

a plurality of character selection members;

a plurality of actuating members with each of said actuating memberscooperating with one of said character selection members;

a rod having a longitudinal axis;

each of said actuating members having a slot therein for mounting saidactuating members on said rod for both pivoting and sliding;

a plurality of typebars with each of said typebars having at least onetype character thereon for printing when said typebar is actuated;

means to connect each of said actuating members to one of said typebars;

pivot means separate from said rod;

means to move each of said actuating members to cause printing of aselected character, said actuating member being slidable relative tosaid rod in a direction substantially perpendicular to the longitudinalaxis of said rod when said cooperating character selection member isactuated to move said actuating member into position for movement bysaid moving means whereby there is no movement of said connecting meansand said typebar; and

said moving means causing both pivoting and sliding of one of saidactuating members after one of said character selection members isactuated to move said one actuating member into position for movement bysaid moving means;

said pivoting of said actuating member initially occurring about thelongitudinal axis of said rod without sliding of said actuating memberrelative to said rod in a direction substantially perpendicular to thelongitudinal axis of said rod, said pivoting occurring about said pivotmeans when said actuating member slides relative to said rod in adirection substantially perpendicular to the longitudinal axis of saidrod.

17. The mechanism according to claim 16 including means on saidactuating member to allow activation of said moving means after saidactuating member has completed sliding movement by said cooperatingcharacter selection member.

18. The mechanism according to claim 16 in which said moving means iscyclic.

19. A mechanism for printing a selected type character at a printingposition comprising:

a plurality of character selection members;

a plurality of actuating members with each of said actuating memberscooperating with one of said character selection members;

a rod;

each of said actuating members having a slot therein for mounting saidactuating members on said rod for both pivoting and sliding;

a plurality of typebars with each of said typebars having at least onetype character thereon for printing when said typebar is actuated;

means to connect each of said actuating members to one of said typebars;

means to move each of said actuating members to cause printing of aselected character, said actuating member being only slidable when saidcooperating character selection member is actuated to move saidactuating member into position for movement by said moving means wherebythere is no movement of said connecting means and said typebar;

said moving means causing both pivoting and sliding of one of saidactuating members after one of said character selection members isactuated to move said one actuating member into position for movement bysaid moving means;

means to activate said moving means;

a separate resilient finger engaging each of said actuating members andadapted to actuate said activating means; and

means on said actuating member to release said resilient finger aftersaid actuating member has completed sliding movement by said cooperatingcharacter selection member, said resilient finger actuating saidactivating means upon release by said releasing means.

20. The mechanism according to claim 19 including:

means on said actuating member engaging said resilient finger after saidresilient finger is released by said releasing means; and

means to vary the resisting force urged by said resilient finger againstsaid engaging means on said actuating member to regulate the force withwhich each of said typebars moves the character thereon into engagementwith a platen to print the character thereon in accordance with the areaof the character.

21. mechanism for printing a selected type character at a prlntingposition comprising: i

a plurality of character selection members;

a plurality of actuating means equal in number to said characterselection members;

15 each of said character selection members cooperating with one of saidactuating means to move said actuating means; each of said actuatingmeans having at least one type character connected thereto for printingat the printing position when said actuating means is actuated; cyclicmeans cooperating with each of said actuating means, said cyclic meansactuating one of said actuating means to print the selected character atthe printing position when said one actuating means is moved by saidcooperating character selection member into a position for cooperationwith said cyclic means; said cyclic means includes:

a reciprocating member having a plurality of resiliently biased fingers;each of said resiliently biased fingers having a slot therein adapted toreceive one of said actuating means whereby movement of said actuatingmeans into said slot results in actuation of said actuating means whensaid reciprocating member is reciprocated; means cooperating with saidactuating means to prevent actuation by said cyclic means of another ofsaid actuating means during movement of said one actuating means by saidcyclic means; and said cooperating means includes a non-slotted portionof said resiliently biased finger engaging said another actuating meansduring movement of said reciprocating member to prevent said anotheractuating means from being moved into said slot in said resilientlybiased finger until completion of a cycle of said reciprocating memberduring which said one actuating means is actuated.

References Cited UNITED STATES PATENTS 1,156,288 10/1915 Hausberg 197-141,178,879 4/1916 Schnyder 197-14 1,455,112 5/1923 Crawley 197-171,927,761 9/1933 TauSChek 197-14 1,955,987 4/1934 Trego 197-14 2,129,8669/1938 Page 197-14 2,521,478 9/1950 Petit 197-17 2,891,649 6/1959Peterson 197-14 3,151,722 10/1964 Salto 197-17 3,191,740 6/1965 Smusz etal 197-107 XR 3,327,828 6/1967 Dannatt 197-16 XR EDGAR S. BURR, PrimaryExaminer U.S. Cl. X.R.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 ,458,024 July 29 1969 John O. Schaefer It is certified that error appears inthe above identified patent and that said Letters Patent are herebycorrected as shown below:

Column 5, line 14, "48)" should read 48.) line 45, "driveshaft" shouldread drive shaft Column 9, line 74, "obsorbed" should read absorbedColumn 12, line 42, claim reference numeral "6" should read 9 line 62,cancel "actuating"; same line 62, after "character" insert at theprinting position when said one actuating Column 13, line 3, claimreference numeral "6" should read 12 line 15, claim reference numeral"9" should read l2 line 24, "membtrs" should read members line 35,"cooptrating" should read cooperating line 36, after "member", firstoccurrence, insert when said cooperating character selection memberSigned and sealed this 28th day of April 1970.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. WILLIAM E. SCHUYLER, JR. Attesting OfficerCommissioner of Patents

